:root {
            --primary-color: #8B4513; 
            --secondary-color: #D2B48C; 
            --accent-color: #A52A2A; 
            --light-color: #F5F5DC; 
            --dark-color: #333333;
            --text-color: #3E2723;
        }
        body {
            font-family: "Noto Serif SC", serif, "Microsoft YaHei", sans-serif;
            color: var(--text-color);
            line-height: 1.8;
            overflow-x: hidden;
        }
        h1, h2, h3, h4, h5, .navbar-brand {
            font-family: "STKaiti", "KaiTi", "楷体", serif;
            font-weight: bold;
            color: var(--primary-color);
        }
        .bg-custom-light {
            background-color: var(--light-color);
        }
        .bg-custom-dark {
            background-color: var(--dark-color);
            color: #fff;
        }
        .text-primary-custom {
            color: var(--primary-color) !important;
        }
        .border-primary-custom {
            border-color: var(--primary-color) !important;
        }
        .btn-primary-custom {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
            color: white;
        }
        .btn-primary-custom:hover {
            background-color: var(--accent-color);
            border-color: var(--accent-color);
            color: white;
        }
        .hero-section {
            background: linear-gradient(rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0.6)), url('https://images.unsplash.com/photo-1560851248-7a2a48efb433?ixlib=rb-4.0.3&auto=format&fit=crop&w=2070&q=80');
            background-size: cover;
            background-position: center;
            color: white;
            padding: 180px 0 120px;
            min-height: 100vh;
            display: flex;
            align-items: center;
        }
        .section-padding {
            padding-top: 80px;
            padding-bottom: 80px;
        }
        .card-hover-effect {
            transition: transform 0.3s ease, box-shadow 0.3s ease;
            border: 1px solid rgba(139, 69, 19, 0.2);
        }
        .card-hover-effect:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
        }
        .teacher-img {
            width: 150px;
            height: 150px;
            object-fit: cover;
            border: 5px solid var(--secondary-color);
        }
        .course-icon {
            font-size: 2.5rem;
            color: var(--primary-color);
            margin-bottom: 1rem;
        }
        .testimonial-img {
            width: 80px;
            height: 80px;
            object-fit: cover;
        }
        footer a {
            color: var(--secondary-color);
            text-decoration: none;
            transition: color 0.3s;
        }
        footer a:hover {
            color: white;
            text-decoration: underline;
        }
        .friendlink {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 20px;
            padding: 20px 0;
            border-top: 1px solid rgba(255,255,255,0.1);
            border-bottom: 1px solid rgba(255,255,255,0.1);
            margin: 30px 0;
        }
        .flink {
            color: #ccc;
            padding: 5px 15px;
            border-radius: 4px;
            background: rgba(255,255,255,0.05);
            transition: all 0.3s;
        }
        .flink:hover {
            color: white;
            background: rgba(255,255,255,0.1);
            text-decoration: none;
        }
        .navbar {
            box-shadow: 0 4px 12px rgba(0,0,0,0.05);
            transition: all 0.3s ease;
            background-color: rgba(255, 255, 255, 0.95);
        }
        .navbar.scrolled {
            background-color: rgba(255, 255, 255, 0.98);
            padding-top: 5px;
            padding-bottom: 5px;
        }
        .sticky-top {
            position: sticky;
            top: 0;
            z-index: 1020;
        }
        .call-to-action {
            background: linear-gradient(to right, var(--primary-color), var(--accent-color));
            color: white;
            border-radius: 10px;
            padding: 40px;
        }
        @media (max-width: 768px) {
            .hero-section {
                padding: 120px 0 80px;
                text-align: center;
            }
            .section-padding {
                padding-top: 60px;
                padding-bottom: 60px;
            }
            .display-3 {
                font-size: 2.5rem;
            }
        }